Effects of a new desensitizing paste containing 8% arginine and calcium carbonate on the shear bond strength of orthodontic brackets / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to evaluate shear bond strength (SBS) and failure site location of brackets bonded to enamel with or without desensitizer application. METHODS: Sixty-six freshly extracted human premolar teeth were randomly divided into 3 groups of 22. Group 1 served as the control. Desensitizer was applied to the remaining teeth at two time intervals (Group 2, bonded immediately after Pro-Relief(TM) (Colgate-Palmolive Co., New York, NY, USA) application and Group 3, bonded 30 days after Pro-Relief(TM) application with the teeth stored in artificial saliva during the 30 days). Orthodontic brackets were bonded with a light cure composite resin and cured with a halogen light. After bonding, the SBS of the brackets was tested using a universal testing device. Adhesive remnant index (ARI) scores were determined after the brackets failed. Data were analyzed with analysis of variance, Tukey's HSD, and G tests. RESULTS: The SBS was significantly lower in Group 2 than in Groups 1 (p = 0.024) and 3 (p = 0.017). Groups 1 and Group 3 did not differ (p = 0.991). ARI scores did not differ significantly among groups. CONCLUSIONS: The Pro-Relief(TM) desensitizer agent applied immediately before bonding significantly reduces bond strength, but the SBS values still exceed the minimum 5.9 - 7.8 MPa required for adequate clinical performance. Immersing the teeth in artificial saliva for 30 days after applying the Pro-Relief(TM) desensitizer agent and before bonding increased the SBS to control levels.

Exposure of Surgical Staff to Radiation During Surgical Probe Applications in Breast Cancer / 한국유방암학회지

PURPOSE: The aim of study was to determine the level of the radiation exposure of surgical staff during surgical probe applications in breast cancer. METHODS: Three operations of a sentinel lymph node biopsy were randomly selected. Spaced circles (50 cm apart) were drawn surrounding the operation bed on the floor. Tc-99m nanocolloid was injected peritumorally and intradermally into a patient. The radiation dose was measured with a GeigerMueller counter placed according to the drawn circles at distances of 50-200 cm from the side of patient's head and bilateral chest while the patient lay on the operation bed. All of the surgical procedures were recorded with a video camera and were monitored. RESULTS: The whole body dose to the senior surgeon was calculated as 2.00-4.70 microSv which means that a senior surgeon can perform 212-500 procedures per year to reach the annual International Commission on Radiological Protection radiation dose limit for a member of the public. CONCLUSION: We concluded that radiation risk to the surgical staff is low from sentinel node detection with the use of radiocolloids.